Yes, it is a light dimmer.
The switch only turns it on and off. Yes, it has a light in the switch. Reversing the blue and purple wires only effects which way the switch turns off and on correct?
I put electrical tape on the back of the front panel in case the TRIAC hits the panel.
There is no ground in the laboratory, which is common in Brazil construction. I don't know why Brazil doesn't use ground wires, other than cost maybe.
The boiler for the still is a stainless steel drum and the column is made of copper. The boiler sits on a steel platform/stand, which sits on the ground. This is in a lab, so I cannot actually ground it like literally with a rod hammered into the ground. There is no ground in the plastic, electrical sockets either. To ground it with a rod, the wire would have to go out a window and down two floors to the ground outside.
Thank You for your help.